spree/spree — pull request #2626 by sbounmy (2013-02-27 21:43:01+00:00)
Title: tab are displayed only if user has :admin right on resource

when having custom ability for admins, we may want users to see only tabs which they have authorization.

Each tab is basically represented by a resource, product, promotion, ...
In order to see a given tab, users should have at least :admin authorization on that resource.

I've changed a little bit tab helper to support that.